This R21 proposal is submitted in response to PA-02-118, Research on Clinical Decision Making for the purpose of operationalizing the four measures of the Transtheoretical Model (TTM) (stages of change, decisional balance, processes of change, self-efficacy) for health care proxy (HCP) completion, and developing models based on the relationships between the stages of change measure and the other three measures. The R21 mechanism was selected because the proposed project uses a theoretical model new to the substantive area and requires development and preliminary testing of new instruments. Completing a HCP provides the means to have one's wishes regarding treatments followed when one can no longer express those wishes. The HCP is an important mechanism for individuals to use "to participate in advance care planning for health care decisions." Historically HCP completion interventions have assumed an action paradigm while ignoring an individual's readiness to change behavior. The TTM provides a promising approach to increase the number of HCPs in the general population by assessing an individual's readiness to change behavior and providing interventions that are matched to the stage of readiness (Long term objective- LTO). The TTM has been used extensively to change risky or encourage health behaviors but not to change a one-time health behavior. The aims of the study are: 1.) To operationalize the four measures of the TTM for HCP completion and evaluate the psychometric properties of the measures; 2.) To test expected relationships between the TTM measures in order to be able to design stage-matched interventions. For aim 1, items for each of the four TTM measures will be constructed, To establish the psychometric properties of each measure, content validity using an expert panel, and construct validity using Cronbach's alpha, and confirmatory factor analysis, will be used. Aim 2 will be accomplished by establishing the relationships between the stages of change and the other three measures and the behavior of interest (completing HCPs) using ANOVA or MANOVA depending on the specific measure to be analyzed. Individuals who are insured by a large managed care organization will be recruited and a representative Sample obtained for data collection, via telephone survey. The outcome of this initial study will provide the investigators with reliable and valid TTM measures to both assess the individual's stage of readiness to complete a HCP, and design stage matched interventions focused on completing a HCP (LTO). [unreadable] [unreadable]